Characteristics of Xu Mai (Deficient Pulse)Today we will learn about the pulse pattern of Xu Mai (deficient pulse), which is categorized under abnormal pulse types.1. Characteristics of Xu Mai:Generally, Xu Mai is considered a general term for all weak pulses. Commonly observed in clinical practice, Xu Mai is characterized by a floating pulse that, while apparent, is softer and weaker than a normal or soft pulse. Both the middle and deep levels of the pulse are distinctly weak, and sometimes the deep pulse may not be palpable at all.The pulse feels floating, large, and soft, with a slow rhythm. Upon slight pressure, it becomes entirely powerless, giving a sensation of subtle movement and an overwhelming emptiness beneath the fingers.Similar pulse patterns to Xu Mai include Fu Mai (floating pulse), Ke Mai (scattered pulse), Ge Mai (leathery pulse), San Mai (dispersed pulse), Wei Mai (weak pulse), Ru Mai (soft pulse), which require careful differentiation.2. Mechanisms and Diagnostic Significance of Xu Mai:1. Qi deficiency;2. Blood loss (often accompanied by Qi loss);3. Yang deficiency (often both Yang and Qi are deficient);4. Yin exhaustion (often both Qi and Yin are deficient);5. Fluid deficiency (often Qi and fluid deficiency, or dryness and heat damaging fluids leading to significant fluid loss);6. Essence deficiency.Any weakness or deficiency of the basic biological active substances that constitute and maintain normal life activities in the human body can lead to Xu Mai. These substances mainly include Qi, Blood, Yin, Yang, Wei (defensive Qi), Jin (body fluids), Ye (nutrients), and Jing (essence). Clinically, Xu patterns can generally be seen as insufficiency, weakness, deficiency, exhaustion, or loss.Whenever Xu Mai is observed clinically, it undoubtedly indicates a deficiency of Zheng Qi (upright Qi). However, two points must be noted: First, the degree of Zheng Qi deficiency varies, leading to differences in the observed Xu Mai, but the common characteristic is the weakness of the pulse. For example, blood loss often presents with a Ke Mai (scattered pulse), while Yin exhaustion may show a Se Mai (rough pulse) or Ying Mai (hard pulse). If exhaustion or loss occurs, it may significantly present with opposing pulse patterns, such as a Da Mai (large pulse) or Tan Zhi Mai (string-like pulse). Second, Qi deficiency is the primary mechanism leading to Xu Mai. Due to the close relationship between Qi, Blood, Yin, Yang, Ying, Wei, Jin, Ye, and Jing in physiological and pathological contexts, the deficiency of the latter eight substances often leads to Qi deficiency, or Qi deficiency may occur alongside the deficiency of these eight substances, such as Qi and Blood deficiency, Qi and Jin deficiency, Yang Qi deficiency, etc. Correspondingly, the deficiency of these eight substances will lead to Qi deficiency, which is also the reason for using Du Shen Tang (Ginseng Decoction) to treat blood loss, as blood loss often occurs with Qi loss. Supplementing Qi can help retain and generate blood. Additionally, these eight substances can influence each other, often causing a chain reaction throughout the body.As for which part of the body or which organ system is experiencing the deficiency, sometimes it can be determined by examining the divisions of the Cun (inch) pulse. If the Cun pulse is deficient, it is often seen in the upper part of the body, indicating deficiency in the exterior or in the heart or lungs, or both. If the Guan (bar) pulse is deficient, it mainly indicates deficiency in the middle jiao (digestive system), particularly the spleen and stomach. If the Chi (cubit) pulse is deficient, it primarily indicates deficiency in the kidneys and lower jiao.3. Diagnostic Significance of Differentiating Xu Mai:To determine which substance or substances among Qi, Blood, Yin, Yang, Ying, Wei, Jin, Ye, and Jing are deficient and causing Xu Mai, a comprehensive judgment must be made in conjunction with the accompanying pulses, as well as the patient’s spirit, complexion, tongue, and symptoms. Often, a combination of the four diagnostic methods is required for accurate assessment.4. Main Diseases Associated with Xu Mai (Plain Language Explanation from Binhuh Pulse Studies):Blood deficiency leads to Xu Mai, while Qi excess leads to strong pulses.(In cases of blood and Qi deficiency, Xu Mai is often observed; in cases of excess pathogenic Qi, strong pulses are commonly seen.)5. Poem on Xu Mai (Plain Language Explanation from Binhuh Pulse Studies):Body Condition Poem:Pressing lightly reveals a large and slow pulse; upon heavier pressure, it feels soft and without limit, akin to an empty valley. Do not mistake Ke Mai (scattered pulse) for a single case; Ke Mai appears large and floating like a tender green onion.(When examining Xu Mai, a light touch reveals a large and slow pulse; with heavier pressure, it becomes even softer and weaker, even giving a sense of extreme emptiness. Both Xu Mai and Ke Mai exhibit a floating and large phenomenon, but the two pulse types are indeed different and should not be confused. Xu Mai becomes increasingly weak with heavier pressure, while Ke Mai, despite being large, has a certain solidity akin to a tender green onion.)Main Disease Poem:Xu Mai with body heat indicates heat injury; spontaneous sweating, palpitations, and anxiety are common; fever due to Yin deficiency must be treated early; nourishing Ying and benefiting Qi should not be delayed.(The appearance of Xu Mai is always due to the deficiency of Zheng Qi. For example, spontaneous sweating due to Wei Qi instability, palpitations due to heart deficiency and blood insufficiency, and anxiety due to heart spirit deficiency, all arise from the initial deficiency of Zheng Qi, hence Xu Mai is often observed. Body heat due to external heat injury occurs when the original Qi is first damaged, thus Xu Mai is seen, and it is necessary to benefit Qi to clear heat; internal heat due to Yin deficiency occurs when Yin is insufficient to nourish Yang, thus it is advisable to nourish Yin to reduce heat. In summary, blood deficiency should nourish Ying, and Qi deficiency should benefit Qi to avoid any errors.)Divisional Poem:Blood not nourishing the heart leads to a deficient Cun pulse; abdominal distension and difficulty in digestion indicate a deficient Guan pulse; bone steaming and atrophy due to blood and essence deficiency are often found in the Chi pulse.(When the heart is in the upper jiao and blood deficiency leads to a lack of nourishment, the Cun pulse is often found to be deficient; in the middle jiao, if Qi deficiency cannot transform, abdominal distension and food stagnation are observed, leading to a deficient Guan pulse; in the lower jiao, if both blood and essence are deficient, leading to bone steaming and atrophy, the Chi pulse is often found to be deficient. The Shen Men pulse is another name for the Chi pulse, not to be confused with the Shen Men acupuncture point.)6. Conclusion:To differentiate Xu Mai, the key point is its large and soft nature; whether at the middle level or with heavy pressure, it remains weak and powerless. The term ‘deficient’ encompasses aspects of Yin, Yang, Qi, and Blood. Yin deficiency pulses are weak and rapid; Yang deficiency pulses are weak and slow; Qi deficiency pulses are deep and weak; Blood deficiency pulses are floating and weak.——————END——————*This article is excerpted from “Sixteen Lectures on Clinical Pulse Studies”; for detailed study, please refer to the original text.
